Switching key



KNVENTOR WILL MM 51 BABCOCF'} ATTORNEY w s BABCOCK swncamc KEY FiledJuly 28. 1949 July 22, 1952 Patented July 22, 1952 SWITCHING KEY WilliamS. Babcock, Jr., Orange, N. J.,assignor to .Federal .Telephone and RadioCorporation, New .York, N. Y., a corporation of Delaware ApplicationJuly :28, 1949,:SerialNo. 107,325

(Cl. ZOO-A1) '6 Claims.

This invention relates to a multiple contact switch of'the key actuatedtype commonly used in the telephone industry.

It is desirable in the telephone communications industry to manufactureelectrical switches of the key operated type which are as small in sizeas possible yet rugged enough to insuretrouble free operation for a'long'period of time. It is also highly desirable to manufacture theswitches at the lowest cost possible so that the equipment utilizing theswitch may be sold on the competitive market.

The known switches of the priorart'have attempted to achieve theseobjects by a slight reduction in the number of small component partsnecessary and byattempting'to reduce the overall size or theswitch'units.

"It'is the main objects of this invention'togreat- 1y reduce the cost ofmanufacturing a switch of the key actuated type and to reduce thesize ofsuch a switch with a corresponding reduction in space requirementson't'elephone equipment utilizing lever type switches. This isaccomplished by eliminating all the usual small parts required as wellas reducing the overall size of theswitch unit 'by means of a novelexchange of motion withinthe switch which allows the use of a muchsmaller switch frame. *By eliminating thesmall parts "found in most key:switches of the prior ,artyit may be-seenthatin addition to thegreatreductionin manufacturing cost due to material and labor savings, I:also eliminate to a large extent many of the "possible'sources offailurein suchswitches.

Another object of this invention is to increase the efficiency :of theswitch by decreasing the number of contact fspring moldings to a-minimum.

A-still furtherobject of my invention is to -provlde removable springcontacts easily replaced and cheaply manufactured in the form of groupunits, allowing 2a "wide variety of switching actions.

It is also "an object of this invention to provide a switch of the typedescribed having novel means'which maybe arranged when manufactured forautomatically returning the switch from 'an operated to a non-operatedposition, or for retaining the'switch in an operated :position or 'forprovdin'g the former actionin one position of operation and the latteraotionina second position of operaition.

The switch of my invention comprises a frame, a lever which is pivotallymounted on theframe for movement in afirst plane, andacradle-likestructure carrying contact actuating surfaces which is pivotally mountedin the path of the lever and is movable in a plane of -motion at rightangles to the lever motion. Apluralityof contact spring units aredisposed in the pathof the actuating surfaces on the cradle-likestructure and are adapted to be moved by these surfaces into contactwith additional spring :members mounted adjacent-to the movablesprings.

The above mentioned and other features and objects of this invention andthe means of iattaining them will become more apparent, and the"invention itself will be best understood :by reference to the followingdescription of an embodiment of the invention taken in conjunction withthe accompanying drawings of which:

Figure 1 is a 'front view of the switch partly in section showing themechanism in cthencnoperated 'or rest position;

Figure '2 is a "sectionalside view of the switch takenalong the line 2-2of Figure 1;

Figure 3 is a sectional side view-of the switch taken on theline 3-3 ofFigure 1;

Figure .4 is a partial front view of the switch showing the mechanism in:one position :of operation;

Figure-5 isasectionalside view of 'the switch in an operatedpositiontaken along the-1ine'5-5 of Figure4; and

Figure 6 is a front view :of a portion of the switch shown to illustratea second position of operation.

Referring now more specifically :to the drawings, and in particular toFigures 1 to 3,-the switch of the invention is shown as comprising ametal frame I of a substantially box like,rectangularshape having cutoutportions to lighten the structure and openings .to receive the lever 2and other components to be described later. The lever -2 is pivotallymountedwithin'the frame by means of the shaft 3, which extends betweenopposite faces of the frame and is secured in holes thereinsubstantially centrally thereof as shown'in Figure 3. Acradle-lilrestructure 4 is pivotally mounted on the frame on pivot :pins 5 securedinopposite sides of the frame "between the shaft 3 and the end of theframe. The cradle-like structure 4 is formed as a substantially U-shapedmember and is adapted to be snapped into place over the pivot pins 5 andheld there by the resiliency of the metal. This type of mountingprovides for ease of assemblage asno tools are required to insert thecradle-like member. Thus the structure 4 is pivotally movable at rightangles to the motionof the lever 2. The lever 2 is provided with a hubportion through which the shaft 3 passes and with extended portions 6 oneither side of the hub. Roller members I and 8 are pivotally fixed tothese portions by means of the bolts 9 and are in substantial axialalignment. The cradle structure 4 has a pair of opposing cam pieces land II mounted thereon at opposite ends of the cradle by means of thescrews I2 which extend through the resilient metal member of thecarriage described above, or by plastic molding such parts onto theresilient metal member. Cam piece I0 is adapted to receive roller 8 ofthe lever 2 when the lever is moved to the left as shown in Figure 1 andcam piece H is adapted to receive roller 1 when the lever is moved tothe right.

With reference to Figures 4 and 5, where the lever 2 is shown in theright hand position of operation, it is seen that when the roller 1 ismoved into engagement with the cam surface [3 of cam piece II, thecradle-structure 4 is displaced about the pivots 5 into a first positionby a transfer of motion at right angles to the motion of the lever 2. Inlike manner movement of the lever to the left hand position in Figure 5would cause the roller 8 to be moved into engagement with the camsurface [4 of cam piece It! and consequently the cradle structure 4would be displaced in an opposite direction again at a right angle tothe motion of the lever 2.

It will be seen by reference to Figures 2 and 5 that the cam surface I 3of cam H is provided with a recessed portion at the lowest point ofengagement with the roller '1. The roller falling into this portion ofthe cam surface will be retained in an operated position until manuallyreturned by the operator. This type of lock provides a great deal offlexibility in the manufacture of the switch for various applications,as it is merely necessary to vary the type of cam carried by thecarriage to provide a looking or non-locking switch action. Although notshown in the embodiment illustrated in the drawings, the cam surface I4of cam I!) could be adapted for holding the key in an operated positionsimilar to cam II, or both cams could be of the non-locking type similarto cam I 0. In addi tion to this novel locking arrangement I have alsoprovided for an alternate type of retaining means which will hereinafterbe described.

The cam pieces [0 and II are provided with an extension l5 preferably ofinsulating material which extends in the opposite direction from the campieces [0 and H and is indented on opposing sides to form the channelsl6 and I1. Disposed in the path of channel I! as shown in Figures 1 and2 are the spring contact members l8 which are moulded in a block memberand secured in the other end of the frame I by means of the bolts 2| orin any desired manner. Channel I6 is associated with the group ofcontact springs l9 which are also contained in the block member 23.Block members 22 and 23 carry spring contact members 24 and respectivelywhich are mounted on either side of block member 20 by means of thebolts 2|. Adjacent surfaces of the blocks 20, 22 and 23 may be formed tonest with each other, as shown in Figures 2 and 3. The bolts 2| extendbetween the springs carried by the respective blocks and are insulatedtherefrom in any desired manner, the springs may be partially cut awayif necessary to provide clearance for the bolts.

The cooperation between channel I! and the spring contact units [8 isshown in Figures 4 and 5 wherein movement of the lever 2 to the rightbrings the channel ll into engagement with the elongated spring membersI8 and displaces these springs against the spring members 24 therebyperforming a plurality of predetermined switching actions depending uponthe type of spring members carried by the blocks 20 and 22. Movement ofthe switch lever 2 in Figure 4 to the left would bring the channelmember it into engagement with spring members 19 carried by block 20 andthis in turn would displace members It against the spring members 25carried by block 23.

It may readily be seen that this type of spring block assembly allowsfor a wide variety of switching actions as it is merely necessary tointerchange additional moulded block members to obtain any combinationof switching actions desired. The blocks are easily removed and insertedin the mounting frame I because all contact springs of any one block arerigidly carried by the block and are positively aligned with opposingcontact springs when mounted in the frame. The contact springsthemselves are provided with apertures or with semi-circular cutouts '26to allow for easy attachment and non-interference of lead wires.

In order to prevent possible overthrow of the lever 2 with resultingdamage to the spring contact members l8 and 19 the lever 2 is providedwith stop extensions 28 extending from the portion 6, which withreference to Figures 3 to 5, are adapted to engage a pin member 21 atthe end of travel in either two positions of operation and therebypositively arrest the motion of the lever. The pin member 2? is mountedin the frame similarly to the shaft 3 and is parallel to and spaced fromthe shaft. Provision is made for readily adding an extra similar stoppin on either side of the central stop pin to lock out one side therebyproducing a single throw key.

In known switches it is often found that an operator, when returning thekey from an operated position to the neutral position, will accidentlyride through the neutral position and make temporary contact in thesecond position of operation. To prevent this possibility in the switchof my invention I provide a frictional drag on the lever which becomeseffective a short distance on either side of the neutral position.

There is mounted on either side of the lever 2 adjacent to the walls ofthe frame and held within the frame by the shaft 3 and pin 21, a pair offriction plates 29. The shaft 3 has pivotally mounted thereon a U-shapedfriction spring member 39 having outwardly flared ends which areresiliently maintained in contact with the friction plates 29 on eachside of the switch as shown in Figure 5. Plates 29 are provided toprotect the frame I from excessive wear, as the frame may be made from asoft material such as aluminum. Extending from friction plate tofriction plate there is a bushing 3i which at all points of travelmaintains the lever member 2 in a fixed position with respect to thesides of the frame and prevents any sideward motion which mighteventually lead to false operation of the switch. The central portion ofthe U- shaped friction spring member 30 is provided with rounded lippedportions 32 adapted to be engaged by a portion of the extensions 28 asshown in Figure 4. With reference to Figure 4 it may be seen that whenreturning the lever 2 to the neutral position the left hand extendedportion accuse 5 of the 'lever '28 will contact the lipped portion 32 ofthe friction spring member 30. This memberwill then be moved with thelever the rest of the way into the neutral position and through thefrictional drag of the contacting portions of the member30 on the plates29, themomentum of the lever and hence the tendency to ride throughtheneutral position will be greatly reduced. .The operation would be thesame when returning the key from th'eother operatedvposiition.

It has been shown in the above 'discussion'that in the particularembodiment of my switch illustrated in the drawings, I have provided aswitch which is adapted to be automatically returned from a firstposition of operation when released by an operator and which will bemaintained in its second position of operation until manually returnedby the operator. This was accomplished by the various arrangements ofthe cam surfaces I3 and I4. In an alternate arrangement this same typeof action is provided for in a slightly different manner. The method ofaccomplishing this will be best understood with reference to Figures 1and 3, wherein a resilient pin member 33, which may preferably be fiat,is mounted in the frame substantially parallel to the shaft 3 and spacedon the opposite side of the shaft from the pin 21 and extends through anopening in the lever 2. The member 33 is provided with a spacer sleeve34 loosely mounted thereon. A roller 35 is centrally mounted on the pinon a bearing 35 and is adapted to be engaged by a cam surface 31provided in the opening in lever member 2. In the neutral position ofthe switch as shown in Figure l, the roller 35 is held in contact withthe indented portion 38 of the cam surface 31. Upon movement of thelever to either of its two positions of operation the cam surface 31acting on the roller 35 causes the pin member 33 to be bent andconsequently the pin member exerts a restoring force on the cam surface.In the right hand position of operation as shown in Figure 4 thisrestoring force will tend to snap the lever back to the indented portion38 when released by the operator.

In Figure 6 I have shown the lever key in the left hand operatedposition wherein the cam surface 31 is provided with a recessed portion39 which is adapted to maintain the lever in an operated position untilreturned under control of the operator.

It will of course be realized that both sides of the cam surface 31 canbe made to automatically return the lever, or can be made according tothe embodiment shown in Figure 6. This would depend entirely on theproposed usage of the switch.

It will become apparent to one skilled in the art that the switch of myinvention is so constructed that it may be assembled very rapidlywithout the use of any complicated jigs, fixtures or tools. The lever 2,carriage structure 4, pin member 33, the friction spring member 30, thestop pin 21 and the contact spring molding blocks 20, 22 and 23constitute all the removable parts of the switch and it has been shownthat these parts are all adapted to be inserted within the frame memberI by various means designed to facilitate rapid assembly without the useof skilled labor or complicated fixtures.

It must be understood that this particular structure has merely beendescribed as one illustration of my invention but could be modified invarious ways-without departing from "the scope of-my invention. Forinstance the resilient pin member '33 maybe-mounted 'on the lever andthe cam surface embedded inthe'frame, or additional 'side by-sidearrangements of contacts could be added by altering' the actuatingsurface of the cradle. a

What is claimed is:

"1. A key -actu'ated switch comprising, -a frame. a leverpivotallymounted'on said frame for move ment in a'first plane, a:cra'dle-"like contact actuating member pivotally mounted on saidframe,means mounted on said contact actuating memher for engaging said leverand transmitting the motion thereof, to said actuating member forpivotal movement in a second plane at right angles to the plane ofmotion of said lever and contact springs mounted in insulating blocksremovably fixed to said frame and being controlled by the movement ofsaid actuating member.

2. A switch comprising a frame, a lever mounted upon said frame formovement in a first plane, a contact actuating member pivotally mountedon said frame for movement in a second plane at right angles to themovement of said lever, said lever having abutments for engaging saidcontact actuating member and moving said member to at least one positionin said second plane and contact springs mounted in said frame operablethrough the movement of said actuating member to make and break apredetermined combination of contacts.

3. A key actuated switch comprising a frame,

a lever mounted upon said frame and pivotally movable in a first plane,a cradle-like structure pivotally mounted on said frame and movable in asecond plane at right angles to said first plane, rollers mounted onsaid lever, means on said cradle-like structure for engaging saidrollers to transmit the motion of said lever to said cradlelikestructure, first contact springs mounted on said frame and disposed inthe path of motion of said cradle like structure, second contact springsmounted on said frame, said cradle-like structure being operative tomove a predetermined combination of said first contact springs intocontact with said second contact springs.

4. A key actuated switch as claimed in claim 3 and further comprising aresilient pin mounted on said frame, a roller mounted around said pinand being positioned centrally thereon, said lever having a slotted camtrack for slidably engaging said roller, said cam track and resilientpin being operative to automatically return said lever to a neutralposition when released and to prevent overthrow of said lever when movedto an operated position.

5. A key actuated switch as claimed in claim 3 and further comprising aresilient pin member mounted on said frame, a roller mounted around saidpin and being positioned centrally thereon, said lever having a slottedcam track for slidably engaging said roller, said lever being adapted tobe rolled from a normal position into two positions of operation, saidcam track and resilient pin being operative to retain said lever in afirst position of operation and to automatically return said lever tosaid normal position from a second position of operation.

6. A switch of the lever actuated type comprising a frame, a leverpivotally mounted on said frame for movement in a first plane, acradle-like structure pivotally mounted on said frame for movement in asecond plane at right angles to 7 said first plane, said lever havingrollers mounted thereon for contacting said cradle-like structure andtransmitting the motion of said lever to said structure, elongatedcontact springs mounted on the frame in the path of motion of saidcradlelike structure, additional contact springs mounted on said frame,ridges in said cradle-like structure being operative to move saidelongated contact springs into contact with said additional contactsprings, a resilient pin mounted on said frame, a roller mounted on saidpin, said lever having a cam track for engaging said roller and being 8operative to hold said lever in an operated position.

WILLIAM S. BABCOCK, JR.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS 10 Number Name Date 1,91 ,623 Douglas June 6, 19332,397,978 Paulus Apr. 9, 1946

